1. Field
Some example embodiments relate to photonic crystal structures, methods of manufacturing photonic crystal structures, reflective color filters and display apparatuses employing photonic crystal structures.
2. Description of the Related Art
Photonic crystal is a material having a crystal structure used to control light. A crystal structure in which a refractive index is repeated in a period results in occurrences of a constructive interference from light of a specific wavelength and a destructive interference from light of other wavelengths, thus forming a specific color. In this way, structural color technology that forms a color by reflecting and interfering light advantageously forms a color of higher efficiency and controls chromaticity more easily compared with technology that forms a color by absorbing light.
In one-dimensional photonic crystals that are most easily fabricated generally, transparent insulating layers of a lower refractive index and a higher refractive index are alternately deposited to control a color of reflected light. However, in one-dimensional photonic crystals, designed colors are formed only with respect to light having a perpendicular incident angle, and colors are shifted to shorter wavelength bands according to Bragg's law as an incident angle becomes smaller. One-dimensional photonic crystals have viewing angles of 5 or less degrees, and thus, applying one-dimensional photonic crystals to devices such as displays is difficult although one-dimensional photonic crystals have higher color formation and reflection characteristics.